运行错过的Quartz作业

Question

I'm using Quartz with Spring to run a specific task at midnight on the first day of the month. I have tested the job by setting my server date & time to be 11:59 on the last day of the month, starting the server and observing the task run when it turns to 12:00, but I'm concerned about cases where the server (for whatever reason) may not be running at midnight on the first of the month.

I'd assumed that misfire handling in Quartz would care for this, but maybe I'm mistaken on that?

Can anyone advise me on how I might be able to handle this? I'd really prefer not to create a job that runs every 'x' seconds/minutes/hours and check to see if I need to run the job if I can avoid it.

I'm also curious as to why I'm not seeing any Quartz related logging info, but that's a secondary issue.

Here is my spring configuration for the task:

<bean id="schedulerService" class="com.bah.pams.service.scheduler.SchedulerService">
    <property name="surveyResponseDao" ref="surveyResponseDao"/>
    <property name="organizationDao" ref="organizationDao"/>
</bean>

<bean name="createSurveyResponsesJob" class="org.springframework.scheduling.quartz.JobDetailBean">
    <property name="jobClass" value="com.bah.pams.service.scheduler.jobs.CreateSurveyResponsesJob"/>
    <property name="jobDataAsMap">
        <map>
            <entry key="schedulerService" value-ref="schedulerService"/>
        </map>
    </property>
</bean>
<!-- Cron Trigger -->
<bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">
    <property name="jobDetail" ref="createSurveyResponsesJob"/>
    <property name="cronExpression" value="0 0 0 1 * ? *"/>
    <!--if the server is down at midnight on 1st of month, run this job as soon as it starts up next -->
    <property name="misfireInstructionName" value="MISFIRE_INSTRUCTION_FIRE_ONCE_NOW"/>
</bean>

<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">

    <property name="autoStartup" value="true"/>

    <property name="quartzProperties">
        <props>
            <prop key="org.quartz.jobStore.class">org.quartz.simpl.RAMJobStore</prop>
            <prop key="org.quartz.jobStore.misfireThreshold">60000</prop>
        </props>
    </property>
    <property name="jobDetails">
        <list>
            <ref bean="createSurveyResponsesJob"/>
        </list>
    </property>

    <property name="triggers">
        <list>
            <ref bean="cronTrigger"/>
        </list>
    </property>
</bean>

Answer 1

MISFIRE_INSTRUCTION_FIRE_ONCE_NOW is for the purpose you mentioned and if you suspect a shutdown of the server(s) you should definitely persist your jobs out of the JVM memory (ex: by using a JDBCJobStore instead of a RAMJobStore).

RAMJobStore is fast and lightweight, but all scheduling information is lost when the process terminates.

http://quartz-scheduler.org/documentation/quartz-2.x/configuration/ConfigRAMJobStore

JDBCJobStore is used to store scheduling information (job, triggers and calendars) within a relational database.

http://quartz-scheduler.org/documentation/quartz-2.x/configuration/ConfigJobStoreTX

Hope it help.

Answer 2

I too have faced the problem of wanting to run the last scheuled job on a server restart.

This is the solution I have found is to go back one time interval for the trigger and calculate what would have been the next firing time. By iterating through all the triggers the most recent time that a trigger should have fired in the past can be determined.

---

Calculate the interval between each firing:

Date nextFireTime = trigger.getNextFireTime();
Date subsequentFireTime = trigger.getFireTimeAfter(nextFireTime);
long interval = subsequentFireTime.getTime() - nextFireTime.getTime();

Find the next firing time for one time until interval in the past:

Date previousPeriodTime = new Date(System.currentTimeMillis() - interval);
Date previousFireTime = trigger.getFireTimeAfter(previousPeriodTime);

I have found that if you are using a CronTrigger this prevents you asking for a fire time in the past. To work around this I modify the start time, so the above snippet becomes:

Date originalStartTime = trigger.getStartTime(); // save the start time
Date previousPeriodTime = new Date(originalStartTime.getTime() - interval);
trigger.setStartTime(previousPeriodTime);
Date previousFireTime = trigger.getFireTimeAfter(previousPeriodTime);
trigger.setStartTime(originalStartTime); // reset the start time to be nice

Iterate through all of the triggers and find the one that is most recently in the past:

for (String groupName : scheduler.getTriggerGroupNames()) {
    for (String triggerName : scheduler.getTriggerNames(groupName)) {
        Trigger trigger = scheduler.getTrigger(triggerName, groupName);
        // code as detailed above...
        interval = ...
        previousFireTime = ...
    }
}

I'll leave it as an exercise to the reader to refactor this into helper methods or classes. I actually use the above algorithm in a subclassed delegating trigger that I then place in a set sorted by previous firing times.